Very attractive! You've really done a great job for this, your first css site!
There is one issue you will need to deal with, and that's text resizing. People who don't have good vision may use a font size larger than you've designed for. When I design pages in css I take that into account so that if someone ups the font size to 150% of the browser default the layout doesn't break. Yours does. When text is resized on your site the text overlaps the header in that small horizontal navigation up top, and it overlaps out of the bottom of your light background and becomes unreadable against the dark background lower down. These are simple things to fix. Simply don't set heights on elements where text needs to resize, and put the backgrounds on the element UNDER the one the text is on, so that the background will get pushed down and always be under the text.
For specific help with this and other css issues you might benefit from joining the
css-discuss group. You've gotten the basics of good css design down, now all you need to do is refine those skills!